Warren Buffett is in talks to exit his $1.1 billion investment in Graham Holdings Co., the former publisher of the Washington Post, after owning the stock for more than four decades.

Graham may swap assets including a business, and possibly shares it holds in Buffett’s Berkshire Hathaway Inc., according to a regulatory filing Wednesday. Omaha, Nebraska-based Berkshire would turn over its Graham stake, if a deal is signed.

Berkshire and Graham “have not agreed on any terms for such a transaction, and may not reach any such agreement,” according to the filing. Buffett’s company may acquire additional shares in Graham if an agreement isn’t reached or could sell its holdings, Berkshire said in the filing.

Buffett’s company owns 1.73 million shares of Graham, a stake of about 28 percent. The stock closed Wednesday at $654.90. Graham’s businesses include the Kaplan education unit as well as television stations and a cable network.

“My first thought was it might involve TV-broadcasting” assets, said Charles De Vaulx, a manager at International Value LLC, which owns Graham Holdings shares, adding that it’s too early to completely assess the scope of a possible deal. Buffett didn’t return a message seeking comment.

Pension Plan

Graham took its name after selling the Washington Post newspaper to Amazon.com Inc. Chief Executive Officer Jeff Bezos last year. As part of the agreement, Bezos assumed the pension obligations of current employees. Graham still is responsible for retired workers. Its defined-benefit pension plan portfolio held $228.6 million in Berkshire stock at the end of September, according to a regulatory filing.

“No transaction will be consummated unless it is in the interest of both parties,” Graham Holdings said in a statement. Berkshire said in the filing that a deal would be structured as a tax-free split-off.

Buffett, 83, pledged in 2011 when he announced his departure from the newspaper company’s board, that he would be available to advise the company’s management. The billionaire has said in letters to investors that he purchased the shares for about $10 million in 1973. He told Berkshire shareholders three years ago that he intended to retain his stake in the company.

Newspaper Enthusiasm

Berkshire has been expanding its newspaper operations in the past two years, buying publications in towns with a strong sense of community, rather than in large cities with more competition among news providers. The enthusiasm for print journalism is a shift for Buffett, who said in 2007 that investors in the industry faced “long-term problems.”

Buffett was a longtime confidant and friend of Katharine Graham, the former Post chairman and CEO who died in 2001. In May, he called her one of his role models and an example of a “super high-grade” woman who didn’t think she deserved praise.

The billionaire also is friends with Don Graham, Katharine Graham’s son and the CEO of Washington-based Graham Holdings, according to Alice Schroeder’s book, “The Snowball: Warren Buffett and the Business of Life.”